Admiral's Order

Raid — If you attacked this turn, you may pay {U} rather than pay this spell's mana cost.
Counter target spell.

Scourge of Fleets

When Scourge of Fleets enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Island

Negate

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Unstable Shapeshifter

Whenever another creature enters, Unstable Shapeshifter becomes a copy of that creature, except it has this ability.

Prosperous Pirates

When Prosperous Pirates enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Pondering Mage

When Pondering Mage enters, look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

Manakin

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Sea Scryer

Silver Myr

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Meneldor, Swift Savior

Flying
Whenever Meneldor, Swift Savior deals combat damage to a player, exile up to one target creature you own, then return it to the battlefield under your control.

Noble's Purse

Noble's Purse enters tapped and with three coin counters on it.
{T}, Remove a coin counter from Noble's Purse: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Gigantoplasm

You may have Gigantoplasm enter as a copy of any creature on the battlefield, except it has "{X}: This creature has base power and toughness X/X."

Vesuvan Shapeshifter

As Vesuvan Shapeshifter enters or is turned face up, you may choose another creature on the battlefield. If you do, until Vesuvan Shapeshifter is turned face down, it becomes a copy of that creature, except it has "At the beginning of your upkeep, you may turn this creature face down."
Morph {1}{U}

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Marching Duodrone

Whenever Marching Duodrone attacks, each player creates a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Disrupting Shoal

You may exile a blue card with mana value X from your hand rather than pay this spell's mana cost.
Counter target spell if its mana value is X.

Beyeen Coast

Beyeen Coast enters tapped.
{T}: Add {U}.

Beyeen Veil

Creatures your opponents control get -2/-0 until end of turn.

Beyeen Veil // Beyeen Coast

Snapback

You may exile a blue card from your hand rather than pay this spell's mana cost.
Return target creature to its owner's hand.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Master of Winds

Flying
When Master of Winds enters, draw two cards, then discard a card.
Whenever you cast an instant, sorcery, or Wizard spell, you may have Master of Winds's base power and toughness become 4/1 or 1/4 until end of turn.

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Illusionist's Stratagem

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.
Draw a card.

Tower Geist

Flying
When Tower Geist enters, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Extraordinary Journey

When Extraordinary Journey enters, exile up to X target creatures. For each of those cards, its owner may play it for as long as it remains exiled.
Whenever one or more nontoken creatures enter, if one or more of them entered from exile or was cast from exile, you draw a card. This ability triggers only once each turn.

Lethargy Trap

If three or more creatures are attacking, you may pay {U} rather than pay this spell's mana cost.
Attacking creatures get -3/-0 until end of turn.

Riverwise Augur

When Riverwise Augur enters, draw three cards, then put two cards from your hand on top of your library in any order.

Juxtapose

You and target player exchange control of the creature you each control with the highest mana value. Then exchange control of artifacts the same way. If two or more permanents a player controls are tied for highest, their controller chooses one of them.

Aether Channeler

When Aether Channeler enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Annul

Counter target artifact or enchantment spell.

Raven Familiar

Flying
Echo {2}{U} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Raven Familiar enters, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Hulking Metamorph

Prototype {2}{U}{U} — 3/3 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
You may have Hulking Metamorph enter as a copy of an artifact or creature you control, except it's an artifact creature in addition to its other types, and its power and toughness are equal to Hulking Metamorph's power and toughness.

Feywild Caretaker

When Feywild Caretaker enters, you take the initiative.
At the beginning of your end step, if you have the initiative, create a 1/1 blue Faerie Dragon creature token with flying.

Flow of Ideas

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Ixidron

As Ixidron enters, turn all other nontoken creatures face down. (They're 2/2 creatures.)
Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

Coldsteel Heart

Coldsteel Heart enters tapped.
As Coldsteel Heart enters, choose a color.
{T}: Add one mana of the chosen color.

Sea Gate Oracle

When Sea Gate Oracle enters, look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

Overwhelming Intellect

Counter target creature spell. Draw cards equal to that spell's mana value.

Micromancer

When Micromancer enters, you may search your library for an instant or sorcery card with mana value 1, reveal it, put it into your hand, then shuffle.

Suspend

Exile target creature and put two time counters on it. If it doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may play it without paying its mana cost. If it's a creature, it has haste.)

Thousand Winds

Flying
Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Thousand Winds is turned face up, return all other tapped creatures to their owners' hands.

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Diluvian Primordial

Flying
When Diluvian Primordial enters, for each opponent, you may cast up to one target instant or sorcery card from that player's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.

Wizards of the _____

When this creature enters, you may put a name sticker on it, then look at the top X cards of your library, where X is the number of unique vowels on that sticker. Put one of those cards into your hand and the rest on the bottom of your library in any order. (The vowels are A, E, I, O, U, and Y.)

Undercover Operative

You may have Undercover Operative enter as a copy of any creature on the battlefield, except it enters with a shield counter on it if you control that creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Deranged Assistant

Phyrexian Ingester

Imprint — When Phyrexian Ingester enters, you may exile target nontoken creature.
Phyrexian Ingester gets +X/+Y, where X is the exiled creature card's power and Y is its toughness.

Chancellor of the Spires

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, each opponent mills seven cards.
Flying
When Chancellor of the Spires enters, you may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Sphinx of Uthuun

Flying
When Sphinx of Uthuun enters, reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Body Double

You may have Body Double enter as a copy of any creature card in a graveyard.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Sphinx of Enlightenment

Flying
When Sphinx of Enlightenment enters, target opponent draws a card and you draw three cards.

Legerdemain

Exchange control of target artifact or creature and another target permanent that shares one of those types with it. (This effect lasts indefinitely.)

Shield Broker

When Shield Broker enters, put a shield counter on target noncommander creature you don't control. You gain control of that creature for as long as it has a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Keep Watch

Mercurial Pretender

You may have Mercurial Pretender enter as a copy of a creature you control, except it has "{2}{U}{U}: Return this creature to its owner's hand."

Quicksilver Gargantuan

You may have Quicksilver Gargantuan enter as a copy of any creature on the battlefield, except it's 7/7.